/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.dtstack.chunjun.connector.ftp.spliter;

import com.dtstack.chunjun.connector.ftp.extend.ftp.IFormatConfig;
import com.dtstack.chunjun.connector.ftp.extend.ftp.IFtpHandler;
import com.dtstack.chunjun.connector.ftp.extend.ftp.concurrent.FtpFileSplit;
import com.dtstack.chunjun.throwable.ChunJunRuntimeException;

import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class ConcurrentZipCompressSplit extends DefaultFileSplit {
    @Override
    public List<FtpFileSplit> buildFtpFileSplit(
            IFtpHandler handler, IFormatConfig config, List<String> files) {
        List<FtpFileSplit> fileSplits = new ArrayList<>();
        for (String filePath : files) {
            fileSplits.addAll(analyseSingleFile(handler, filePath, config.getEncoding(), "ZIP"));
        }

        fileSplits.sort(compare());
        return fileSplits;
    }

    private List<FtpFileSplit> analyseSingleFile(
            IFtpHandler ftpHandler, String filePath, String encoding, String compressType) {

        List<FtpFileSplit> fileSplits = new ArrayList<>();
        try (java.util.zip.ZipInputStream zipInputStream =
                new ZipInputStream(
                        ftpHandler.getInputStream(filePath), Charset.forName(encoding))) {
            ZipEntry zipEntry;

            while ((zipEntry = zipInputStream.getNextEntry()) != null) {
                fileSplits.add(
                        new FtpFileSplit(
                                0, zipEntry.getSize(), filePath, zipEntry.getName(), compressType));
            }
            return fileSplits;
        } catch (Exception e) {
            throw new ChunJunRuntimeException(e);
        }
    }
}
